Most restraint belt retractors used in present-day vehicles have a winding or return spring which continuously acts on the reel and maintains tension in the belt. After even a relatively short time, the pressure of the tensioned belt against the occupant's body becomes bothersome to the occupant, often so much so that he or she is inclined to disconnect the belt with the obviously harmful results of no longer being restrained and being in great danger in the event of an accident or sudden stop. It is, therefore, very desirable that a belt retractor has some device for locking the belt in a comfortable, safe configuration, but that is not easy to do, given the variations in the sizes and sitting postures or vehicle drivers and passengers. Moreover, it is also desirable that such a device not restrict the occupant's movements, such as leaning forward to operate dashboard controls. It should respond reasonably promptly to changes in the occupant's sitting posture, but it should not respond so quickly as to lock against rewinding when it is not properly fitted to an occupant who has settled into a comfortable position.